> -----Original Message-----
> From: Roger Pau Monne [mailto:roger....@citrix.com]
> Sent: 08 October 2018 14:53
> To: xen-devel@lists.xenproject.org
> Cc: Roger Pau Monne <roger....@citrix.com>; Jan Beulich
> <jbeul...@suse.com>; Paul Durrant <paul.durr...@citrix.com>
> Subject: [PATCH v2] x86/vtd: fix iommu_share_p2m_table
>
> Commit 2916951c1 "mm / iommu: include need_iommu() test in
> iommu_use_hap_pt()" changed the check in iommu_share_p2m_table to use
> need_iommu(d) (as part of iommu_use_hap_pt) instead of iommu_enabled,
> which broke the check because at the point in domain construction
> where iommu_share_p2m_table is called need_iommu(d) will always return
> false.
>
> Fix this by reverting to the previous logic.
>
> While there turn the hap_enabled check into an ASSERT, since the only
> caller of iommu_share_p2m_table already performs the hap_enabled check
> before calling the function.
>
> Signed-off-by: Roger Pau Monné <roger....@citrix.com>
Reviewed-by: Paul Durrant <paul.durr...@citrix.com>
> ---
> Cc: Jan Beulich <jbeul...@suse.com>
> Cc: Paul Durrant <paul.durr...@citrix.com>
> ---
> Changes since v1:
> - Add a comment about why iommu_use_hap_pt cannot be used in
> iommu_share_p2m_table.
> - Expand commit message.
> - Convert the hap_enabled check into an ASSERT.
> ---
> xen/drivers/passthrough/iommu.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/xen/drivers/passthrough/iommu.c
> b/xen/drivers/passthrough/iommu.c
> index debb5e6fe1..75bc410c2c 100644
> --- a/xen/drivers/passthrough/iommu.c
> +++ b/xen/drivers/passthrough/iommu.c
> @@ -505,7 +505,13 @@ int iommu_do_domctl(
>
> void iommu_share_p2m_table(struct domain* d)
> {
> - if ( iommu_use_hap_pt(d) )
> + ASSERT(hap_enabled(d));
> + /*
> + * iommu_use_hap_pt cannot be used here because at the point in the
> domain
> + * construction where iommu_share_p2m_table get called need_iommu(d)
> will
> + * always return false.
> + */
> + if ( iommu_enabled && iommu_hap_pt_share )
> iommu_get_ops()->share_p2m(d);
> }
>
> --
> 2.19.0
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